1. Field of the Invention
The present invention relates to a high frequency amplifier, in particular, the multi-space structure amplifier which may amplify various frequencies through use of the Gunn diode installed in the multi-space structure non-radiative dielectric waveguides of various different sizes.
2. Description of Related Art
As the computer and information communication technologies improve, data amount used by individuals increases accordingly. Furthermore, because of the recent development of multimedia, the formats of information used by individuals are changing from texts of characters to paintings or pictures, and further to motion pictures. Thus, there exists an urgent need to transmit a large quantity of information by real time.
For the above-described reasons, uses of mobile or cellular terminals are steadily increasing and thus the need also increases for a high capacity super-high speed radio communication device which may transmit a large amount of information to such cellular terminals.
Therefore, it is necessary to use high frequency and widened bandwidth and there are acute demands for amplifiers which can process high frequencies and provide broadbands.
A Gunn diode of GaAs material is an element with two conduction band valleys, which may be in a negative resistance state according to the difference in electronic mobility, which is caused by the element""s electric field strength.
As the bias voltage is applied to a Gunn diode, two amplification areas and one oscillation area are generated, as illustrated in the graph of FIG. 1. Here, the amplification area at the lower bias voltage level is called xe2x80x9cAmplification Area 1xe2x80x9d and the amplification area at the higher bias voltage level is called xe2x80x9cAmplification Area 2.xe2x80x9d The Amplification Area 1 at the lower bias voltage is the negative resistance area where the electrons inside of the Gunn diode move from L valley to U valley. Such negative resistance area continues until there is no gain in Amplification Area 2. As the graph illustrates, there are two negative areas in the Gunn diode, but in Amplification Area 1, there is only a very limited scope where the bias voltage may be supplied. Such amplification area may be easily escaped by instability of the bias circuit. Thus, an amplifier may be designed for Amplification Area 2.
An amplifier designed using Amplification Area 2 may have a problem of inability to carry various frequencies, because all the circuit elements constituting the amplifier, such as dielectric waveguides and a strip resonator, are set to resonate in accordance with a certain predetermined frequency.
In order to solve the above-described problems, the present invention has its object in providing an amplifier with the non-radiative dielectric waveguides, using the amplification characteristics of the Gunn diode.
The non-radiative dielectric waveguide requires the Gunn diode""s size to be changed for amplification of a different frequency, because circuit elements must be installed between two metal plates, the space between which is a half the frequency to be used. Another object of the present invention is to provide an amplification function for various frequencies regardless of the size of the Gunn mount, by using the multi-space structure non-radiative dielectric waveguides, in order to overcome problems related to the Gunn diode size.